Ministers are considering raising the minimum legal age for buying tobacco in England from 16 to 18, the Department of Health has said.
A raised limit would be in line with the US and other EU states
Campaigners argue bringing the law on cigarettes into line with that on alcohol would reduce under-age smokers.
The government has promised to look into their evidence, but department sources told the BBC the law was unlikely to change in the near future.
In Scotland, MSPs are already looking at raising the minimum legal age to 18.
BBC political correspondent Sean Curran said: "Health department sources insist no decisions have been taken and say the law is unlikely to change in the near future."
Public places ban
The proposals to protect under-18s won backing from groups on all sides of the smoking lobby.
"I think it's important to emphasise that smoking is an adult activity and anything that can discourage children from smoking is a good thing," Simon Clarke from the pro-smoking group Forest told BBC Radio Five Live.
But he said it would be difficult to enforce a new law.
However, Colin Finch, legal and parliamentary representative from the National Federation of Retail Newsagents reckoned life would be easier for shop-owners if the age was raised.
The Royal College of GPs and anti-smoking group Ash both welcomed the proposals but questioned government motives.
"If we can make it a little bit more difficult for teenagers to start smoking then hopefully by the time they get to be a bit older they will be more aware that they are not immune to the effects of smoking," said Dr Sarah Jarvis from the Royal College of GPs.
But she said the move could be seen an attempt to divert attention away from some MPs' criticism of its Health Bill, which would bring in a partial smoking ban in public places.
"I am quite convinced that that is exactly what they are doing," she said.
Ian Willmore from Ash described the news as a "rather transparent government attempt to change the subject".
"The Government's run into serious trouble over the Health Bill because it's produced these absurd proposals for banning smoking in public places but continuing to allow them in many pubs and clubs," he said.
Labour MP Jeff Ennis tabled a Commons motion in June to raise the minimum age in England to 18, which has been supported by more than 50 MPs.
Last week Mr Ennis said he would be tabling an amendment to the Health Bill - which will bring in the new rules on smoking in public - to raise the smoking age.
Mr Ennis sits on the committee which will scrutinise the bill.
A spokesman for the Department for Health said: "It is something that we are considering."
A poll conducted last year for the BBC found that four out of five people backed lifting the legal age to 18.
Of the 1,010 adults surveyed, 55% said the minimum age should go up to 21.
Meanwhile, nine out of 10 supported increasing the penalties for selling tobacco to children.